基于NURBS曲线拟合的微段高速自适应加工算法

摘要

In order to actualize the high speed and high quality machining, and improve the micro --segment processing, which had the faults of too large capacity of the NC files and frequent accelera- tion/deceleration controlling in the machining process,a high--speed adaptive NURBS fitting method was developed to actualize the smoothing milling, which was under the constraints of least square ap- proximation algorithm and weight factors of data points. The new fitting algorithm was a high--speed adaptive interpolation algorithm based on NURBS fitting for micro sections. The key of the new algo- rithm was to fit the micro sections into a new tool path made of NURBS. And then, the new tool path can be interpolated easily by the NURBS interpolation algorithm. Under this method, the machining with micro sections of tool path will be smooth and efficient.%为了满足加工精度的要求,消除以微小直线段离散化自由曲线加工路径的微段加工方式的加工程序量过大和需要频繁加减速的两大弊病,实现微小直线段的高速平滑加工,提出了带权因子和一阶导数约束的NURBS曲线最小二乘逼近算法,并在此基础上给出了基于NURBS曲线拟合的微段平滑加工算法。该微段平滑加工算法将离散的微段数据点拟合成一条NURBS曲线并将其作为新的加工路径,然后利用NURBS曲线实时插补,从而实现微小直线段的平滑加工。验证结果表明,该算法使加工更平滑和高效。